mrsa 11.01.2009 american journal of surgery

8/7/2019 MRSA 11.01.2009 American Journal of Surgery

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The Association of VA Surgeons

Implementation of a methicillin-resistant Staphylococcusaureus (MRSA) prevention bundle results in decreasedMRSA surgical site infections

Samir S. Awad, M.D.*, Carlos H. Palacio, M.D., Anuradha Subramanian, M.D.,Patricia A. Byers, R.M., M.(A.S.C.P.), C.I.C., Paula Abraham, R.N., Dr.P.H.,

Debra A. Lewis, M.S., R.N., Edward J. Young, M.D.

Michael E. DeBakey Department of Surgery, Baylor College of Medicine, and Michael E. DeBakey Veterans Affairs

Hospital, Houston, TX, USA

AbstractBACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) surgical site infections (SSIs)

increase morbidity and mortality. We examined the impact of the MRSA bundle on SSIs.

METHODS: Data regarding the implementation of the MRSA bundle from 2007 to 2008 wereobtained, including admission and discharge MRSA screenings, overall MRSA infections, and cardiac

and orthopedic SSIs. Chi-square was used for all comparisons.

RESULTS: A significant decrease in MRSA transmission from a 5.8 to 3.0 per 1,000 bed-days (P.05) was found after implementation of the MRSA bundle. Overall MRSA nosocomial infections

decreased from 2.0 to 1.0 per 1,000 bed-days (P .016). There was a statistically significant decrease

in overall SSIs (P .05), with a 65% decrease in orthopaedic MRSA SSIs and 1% decrease in cardiac

MRSA SSIs.

CONCLUSION: Our data demonstrate that successful implementation of the MRSA bundle signif-icantly decreases MRSA transmission between patients, the overall number of nosocomial MRSA

infections, and MRSA SSIs.

Published by Elsevier Inc.

KEYWORDS:MRSA;

Surgical site infection;

MRSA bundle

Staphylococcus aureus is a ubiquitous organism found

even as normal human flora. It can produce a variety ofclinical presentations ranging from cellulitis to severe sep-

sis. Methicillin-resistant Staphylococcus aureus (MRSA)

was first isolated in the early 1960s. A short 20 years later,

the first community-acquired MRSA (CA-MRSA) infection

was found in individuals who were not affiliated with

healthcare centers. Crum et al demonstrated that since 2002,

cases of CA-MRSA infections increased significantly, with

intrafamilial transmission being a significant cause.1

Fur-thermore, locations such as daycare centers, prisons, and

military installations, as well as intravenous drug abuse,

facilitate the spread of MRSA.2

Over the past decade, the prevalence of MRSA carriers

has increased ranging from 3.7% to 20%.3 Surgical site

infections (SSIs) are defined as those infections presenting

up to 30 days after a surgical procedure if no prosthetic is

placed and up to 1 year if a prosthetic is implanted in the

patient. In the United States, SSI is a serious complication

with an incidence of 2% to 5% in patients undergoing

* Corresponding author. Tel.: 1 713 794 8026; fax: 1 713 794 7352.

E-mail address: [email protected]

Manuscript received May 6, 2009; revised manuscript June 9, 2009

0002-9610/$ - see front matter Published by Elsevier Inc.

doi:10.1016/j.amjsurg.2009.07.010

The American Journal of Surgery (2009) 198, 607610
mailto:[email protected]:[email protected]


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surgery.4 Overall, SSI is the second most common nosoco-

mial infection (24%); most cases are preventable by adher-

ing to appropriate prevention practices. MRSA SSI has been

known to significantly increase postoperative length of stay,

cost, and mortality.4

The Centers for Medicare and Medicaid Services (CMS)

announced that after October 1, 2008 it will not compensate

for preventable acquired conditions, including SSIs, after an

elective surgical procedure, specifically mediastinitis after

coronary artery bypass surgery. Beginning in October 2009,

other conditions being considered for nonpayment include

SSI after total knee replacement, S aureus septicaemia, and

Clostridium difficile infections. Also, CMS is considering

adding MRSA infections to this list of conditions for nonpay-

ment.5 Therefore, successful prevention measures against nos-

ocomial infections must be implemented to improve patient

outcomes by reducing morbidity and mortality.

Given these data concerning the high prevalence of

MRSA SSI and potential high costs, surgeons must be

informed not only of the current treatment options, but also

of preventative measures for transmission in the hospital

setting. In late 2006, our hospital implemented a MRSA

prevention bundle to decrease MRSA transmission and nos-

ocomial infections. Our objective was to examine the im-

pact of the MRSA bundle on SSIs.

Methods

After approval of the Baylor College of Medicine Insti-

tutional Review Board, patients were identified with MRSA

infections at the Michael E. DeBakey Veterans Affairs

Medical Center (MED VAMC). Data were collected from

October 2005 to October 2008 and included demographicinformation, comorbid conditions, initial MRSA nasal screen-

ing results, each subsequent culture result on transfer to a

different unit and at discharge, and presence of MRSA

and/or C difficile infections.

The MRSA bundle was initiated in 1 medical unit in

October 2006 and then implemented hospital-wide by Oc-

tober 2007. Data were collected retrospectively from Octo-

ber 2005 to October 2006, while November 2006 to October

2008 data were collected prospectively. The MRSA bundle

has 5 components: (1) MRSA nasal screening of patients

upon admission, transfer, and discharge; (2) contact isola-

tion of positive patients; (3) standardized hand hygiene;(4) cultural transformation campaign with staff and leader-

ship engagement through positive deviance; and (5) ongo-

ing monitoring of process and outcome measures. MRSA

screening was performed via nasal swab and analyzed by

the GeneXpert MRSA polymerase chain reaction (PCR)

assay (Cepheid, Sunnyvale, CA) with results available in 70

minutes. Descriptive statistics were used to summarize the

characteristics of the patients, prevalence of MRSA per

year, and rates of MRSA transmission. All data are pre-

sented as means SD. Univariate analysis was performed

using the chi-square test.

Results

From 2007 to 2008 all patients admitted to the MED

VAMC were screened for nasal MRSA. During the study

period, we observed a trend toward an increase in effective-

ness in MRSA screenings on admission and discharge from94% and 82% in 2007 to 95% and 86% in 2008, respec-

tively (P not significant [NS]). However, the prevalence

of MRSA did not change and remained 18% of all admitted

patients (Table 1). After implementation of the MRSA bun-

dle there was not only a significant decrease in MRSA

transmissions from 5.8 per 1,000 bed-days in 2007 to 3.0

per 1,000 beds days in 2008 (P .05), but also a significant

decrease in overall MRSA nosocomial infections from 2.0

to 1.0 per 1,000 bed-days (P .016; Table 2). After im-

plementation of the MRSA bundle, there was a statistically

significant decrease in overall SSI (P .05). Although not

significant, the orthopedic MRSA SSI decreased by 65%

(P NS) and cardiac MRSA SSIs decreased by 1% (P

NS). We also observed a decrease in nosocomial MRSA

bloodstream infections per 1,000 bed-days of care from 2.9

in 2006 to 2.5 in 2008 (P NS).

Before the implementation of the MRSA bundle, the rate

of hospital-acquired MRSA infections peaked at 7 per 1,000

bed-days of care. After the initiation of the MRSA bundle in

a medical unit then subsequently hospital-wide, a decreas-

ing linear trend was observed (Figure 1). In addition, the

total C difficile infections, which were used as a surrogate

for nosocomial infections, decreased, as did the rate afterimplementation of the MRSA bundle (Figure 2).

Table 1 Prevalence and screening rates for admittedpatients

Variable 2007 2008

Prevalence of MRSA 18% 18%MRSA screening on unit admission 94% 95%MRSA screening on unit discharge 82% 86%

Table 2 Impact of MRSA bundle on MRSA transmission andinfection

Variable 2007 2008 P

MRSA

transmissions 5.8 per 1,000 BD 3.0 per 1,000 BD .05MRSA infections 2.0/1,000 BD 1.0 per 1,000 BD .016

BD bed days.

608 The American Journal of Surgery, Vol 198, No 5, November 2009


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Comments

Staphyloccocus aureus has become a persistent pathogen

in the community and hospitals throughout the world. Theappearance of antibiotic resistance was first detected in

1961, giving rise to the term MRSA, and followed by the

first documented CA-MRSA infection in 1980.1 Since then,

the incidence and prevalence of MRSA has increased at

alarming rates. According to data from the National Noso-

comial Infection Surveillance System (NNIS) there has

been a continued annual increase in MRSA cases with a

peak increase of nearly 60% in 2004.6 In 2006, a 15-year

study by Crum et al demonstrated an increase in incidence

of CA-MRSA beginning in 2002between 2002 and 2004

there was an over 200% increase in cases CA-MRSA pre-

ceded by 10 years of negligible change.1

Our study illustrates that the prevalence of MRSA in

admitted patients remained the same during the 2-year study

period at 18% and is consistent with what has been reported

in the literature. A recent prospective multicenter study

found an overall MRSA colonization prevalence ranging

from 3.7% to 20%, and specifically in surgical intensive

care units (ICU), a prevalence of 10.3%.3 Furthermore, we

observed an increase in effectiveness of MRSA screening

from admission and discharge comparing both years of our

study. We credit this increase in effectiveness to education

of clinical staff in appropriate techniques of hand washing,

measuring compliance with culture collections, and rapidPCR identification of MRSA-positive cultures. Outcome

measures are tracked on each unit, and data are updated

monthly. Meetings involving all staff are scheduled to discuss

unit data, including admission swabbing rates, discharge/unit

transfer swabbing rates, number of patients colonized, number

of patients with healthcare-acquired infections, and hand hy-

giene compliance.

Several risk factors account for the rise in MRSA infec-

tions, including transmission in healthcare settings, over

antibiotic-prescribing practices, and new, more virulent

strains.7 Many investigators describe the carrier state of

MRSA as an important risk factor for subsequent infection.8

Approximately 10%40% of individuals without hospital

contact are colonized with MRSA in their nares, and up to

7% of healthcare workers are also carriers of MRSA.9 The

reservoir size has been identified as the dominant factor in

the spreading of MRSA to new patients. Caregivers con-

taminated hands are accredited as the most frequent form

of transmission.8 Transmission can occur by skin to skin

contact or contact with contaminated inert objects such as

stethoscopes and blood pressure cuffs.9

A recent studyshowed an increased risk of 4% among those patients whose

prior room occupant was MRSA-positive.10 Therefore, pre-

vention in transmission can be achieved with proper hand

hygiene before moving to another patient, adequately dis-

infecting personal equipment such as stethoscopes, and

thorough cleansing of hospital room daily and after patient

discharge.8

SSIs occur in 2%5% of patients undergoing surgery in

the United States. SSIs are responsible for an increase in

hospital stay and mortality and are associated with signifi-

cant costs, especially when the SSI is caused by resistant

bacteria such as MRSA.11

The presence of an SSI doublesthe risk of death, while the presence of an MRSA SSI

increases the risk of death 11-fold after surgery. Seventy-

seven percent of these deaths are caused directly by the SSI,

with S aureus being the most common cause. A study by

Anderson et al analyzing the impact of S aureus on SSI

revealed an increase in mortality rates, longer hospitaliza-

tion, and increase hospital cost in elderly patients when

compared with uninfected patients with similar age. When

SSI is caused by MRSA the hospital stay can increase by as

much as 2 weeks.12 During 2005, a total of 1,010 SSIs

occurred in a study of 26 hospitals, in which S aureus was

found in as many as 331 (37%) patients, and of these 175(53%) were due to MRSA. In this study, MRSA was the

single most common pathogen isolated.3

While the rising levels of MRSA are frightening, other

issues are cause for alarm. The latest reports illustrated an

increased incidence of invasive MRSA infection on people

who had healthcare encounters within the previous year.7

MRSAs high human and financial impact has led to na-

Figure 2 Clostridium difficile infection rates over time. Short

white arrow: MRSA bundle implementation in 1 U. Long blackarrow: hospital-wide MRSA bundle implementation.

Figure 1 Variations of MRSA infection rate per 1,000 bed-daysof care. Short white arrow: MRSA bundle implementation in 1 U.

Long black arrow: hospital-wide MRSA bundle implementation.

609S.S. Awad et al. MRSA prevention decreases surgical infections


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tional mandates of preventive measures and individual hos-

pitals developing aggressive protocols to decrease nosoco-

mial MRSA colonization and infection. In general, the costs

of screening and preventive actions are less than the cost of

caring for MRSA-infected patients.8 Different programs for

MRSA infection control apply a combination of interven-

tions rather than a single approach.8

The Institute of Healthcare Improvement (IHI) recom-mends reducing MRSA infection by using the following 5

components of prevention: (1) hand hygiene; (2) decontam-

ination of environment and equipment; (3) active surveil-

lance cultures; (4) contact precautions for infected and

colonized patients; and (5) device bundles, such as catheter-

related bloodstream and ventilator-associated pneumonia

bundles.10 Our MRSA bundle is identical to the 1 recom-

mended and included an ongoing monitoring process and

outcome measures. After implementation of the above

MRSA bundle, we observed a significant decrease in MRSA

transmission and overall MRSA nosocomial infection rate.

Our results correlate with other published reports, specifi-cally a recent study by Huang et al, which demonstrated a

decrease (75%) in MRSA bacteremia after implementation

of nares surveillance of MRSA and contact isolation pre-

cautions in ICU patients during admission and weekly

thereafter.13 Another study showed a decrease of 70% in

MRSA infections in 1 patient care unit after implementation

of a bundle of interventions.8

Overall, our SSI rate significantly decreased after imple-

mentation of the MRSA bundle with an observed decrease

in cardiothoracic and orthopedic surgery patients. To our

knowledge this is the first report demonstrating this effect.

This observed decrease correlates with a decrease in trans-mission of MRSA in the hospital, as well as a general

decrease in nosocomial infections. This can be attributed to

improving infection awareness and compliance with hy-

giene practices.

It is important to emphasize that prevention measures

cannot only decrease MRSA prevalence but also affect

other antibiotic-resistant pathogens such as vancomycin-

resistant enterococci and C difficile. The cases of MRSA

and C difficile infection during the study period decreased

after the MRSA bundle was implemented. Some authors at-

tributed this to decreased use of MRSA antibiotics, such as

clindamycin, since these antibiotics predispose patients to Cdifficile infections.8 However, we think the decrease in C

difficile infections is because of the bundle implementation,

especially the compliance with hand hygiene and increased

attention to environmental cleaning.

The limitations of the study include that MRSA screen-

ings were performed using PCR analysis, which allowed for

rapid identification of MRSA from the nares but did not

allow for genetic testing of the isolates to determine if they

were community- versus healthcare-associated strains. For

screening it is not imperative to identify the strain of MRSA

since isolation precautions will be undertaken for any pos-

itive patient as part of the bundle. However, when an infec-

tion does occur, genetic information regarding the MRSA

isolate may be helpful in treatment options. Another limi-

tation was the use of administrative data from the Infection

Control database, which did not allow for accurate length of

stay data to determine the impact of cost secondary to an

MRSA SSI. However, Engemann et al estimate that an

MRSA SSI costs approximately $118,500 compared with

$73,000 for a methicillin-senstitive S aureus (MSSA) infec-tion. The difference of approximately $45,000 per infection

can result in a significant cost savings even if 1 infection is

prevented using the MRSA bundle.11

In summary, our data demonstrate a significant decrease

in MRSA transmission between patients, as well as a de-

crease in the overall number of nosocomial MRSA infec-

tions and MRSA SSIs after a hospital wide implementation

of a MRSA prevention bundle. Additional studies on earlier

identification of MRSA positive patients undergoing a sur-

gical procedure through preoperative screening may de-

crease the incidence of MRSA further and will be the next

step in our campaign against SSIs.

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